python - Django how to make form fields optional -


How to make the form field optional in the DNS?

My model, 

  class students (models.Model): first_name = model. Kharefild (max_long = 30) last_name = models.CharField (max_length = 40) email = Models.EmailField ()    
 
 
 assuming that you want to create  last_name  optional, you can use the attribute:  
  class.model: First_name = models.CharField (max_length = 30) last_name = models.CharField (max_length = 40, empty = true) Email = models.EmailField ()   
 Note that  CharField < On / code> and  TextField , you probably do not want to set  blank  (as for why to discuss See), but on other field types, you will need to, or you will not be able to save examples where the optional values ​​are omitted.

Comments

Post a Comment

Popular posts from this blog

c# - passing input text from view to contoller with FacebookContext using Facebook app -

I'm trying to pass an input text from the viewer to the controller in the Facebook Birthday app: Link to app: In the Home Controller [FacebookAuthorize ("email", "user_photos")] Public async Tasks & lt; ActionResult & gt; Index (FacebookContext reference) {if (ModelState.IsValid) {var user = waiting for reference. Client.Gate CurrentUserAsync & lt; MyAppUser & gt; (); View return (user); } See Return ("Error"); } [Http post] [facebook authorized ("email", "user_photo")) public async task & lieutenant; Actionsclass & gt; Index (string textile, facebookcontonte context) {if (ModelState.IsValid) {var user = wait context.Client.GetCurrentUserAsync & lt; MyAppUser & gt; (); // See my code, see the use of txt here (user); } See Return ("Error"); } View: @using facebookpostc.models @ Microsoft.AspNet.Mvc.Facebook.models using @ Microsoft.AspNet.Mvc. Facebook @model MyAppUser @ {ViewB...
Read more

ios - Does Core Data autoupdate a many to many relationship on saving -

I have used 2 database tables and core data / NSManagedObjects in SQLite: User is user_id name group (multiple groups) Group group_id title group members (multiple users) By using core data to save a group and adding users ( Add to group) as follows: group * cordata = zero; Cordata = [NSEntityDescription insertNewObjectForEntityForName: @ Managed Object Contains in "Groups": Reference]; Request = [NSFetchRequest fetchRequestWithEntityName: @ "user"]; Request.predicate = [NSPredicate predicateWithFormat: @ "user_id =% @", user_id]; Result = [reference executeFetchRequest: request error: & amp; Error]; CoreData.group_id = group_id Cordettitle = Title [Cordata AdGroupMailersObject: [Last objections result]]; Is it right to say that core data manages a user with multiple users and groups with the code above? Yes, if the relationships are in the form of each other's inverse relationship The inverse relationships are updated automaticall...
Read more

Calling a C++ function from C# by passing a string with variable size to it -

I am calling a string with a C + code and calling from the C # code. The C ++ function is responsible for filling the string material. The following code is: C #party: var abc = new string builder (4096); // will have to change this var result = Basic methods. SignCrcFile (ABC); C ++: bool __cdecl SignCrcFile (char * abc) {... char * tempStr = "hello all"; // for example // copy it to ABC string strcpy (ABC, tempStr); Back true; } The problem is that tempStr's size in the C ++ function is dynamic (the above assignment for TempStr is only an example). In such a case, it is not a hard code that the size of ABC string is in the size of 4096 bytes on the C #. The first solution can be a solution to create 2 functions on the C ++ side to get the size of the string. Then allocate that size using StringBuilder in the C # side then use the next function to bring the entire string from C ++ to the C #. But no suggestion this may not be the most optimal way? ...
Read more